Author Archives: Jürgen

Seaweek 2017

To celebrate Seaweek (4-10 Sep. 2017), State Herbarium Hon. Research Associate Bob Baldock wrote the following article for this blog…

Looking towards the west – seaweeds tell the tale of South Australia’s marine connections

The State Herbarium houses about 90,000 specimens of seaweeds (algae), collected over some 160 years. Why so many? and why for so long?

Hypoglossum harveyanum, a rare red alga looking as if it is on fire, and even more striking under the microscope (right image). Photo: R.N. Baldock.

Well, southern Australia has more marine species belonging (that is, endemic) to our region than any other place in the world. Surprisingly, this includes the Great Barrier Reef (GBR), which, although it has more species, shares many of them with other regions. Some think we should call our region the GSR – The Great Southern Reef – just to highlight this (Bennett et al. 2015). We have some species that have only been collected a few times (such as Hypoglossum harveyanum, above). Will we ever find them again?

Satellite image of surface sea temperature. Source: www.cmar.csiro.au

And we also need to know if numbers, types and distributions of species are changing over time, hence the need to collect, preserve and catalogue specimens. How else will we know if climate change is affecting our coastal marine plants and animals? The vast amount of information in the Herbarium’s collections is available to answer some of these questions (Wernberg et al. 2011).

Where does southern Australian marine diversity come from?

Our continental neighbours, Africa and South America, dip further south than Australia They have a south to north distribution of marine species, related to ocean currents. But in Australia, we have a west to east warm current, the Leeuwin, that sweeps across the south of our continent. This current has peculiar swirling characteristics, seen from space that trap subtropical species and carry them as far as the SE of South Australia (Wernberg et al. 2013).

A mix of the cool water red alga Griffithsia teges and several species of green Caulerpa, a genus usually found in tropical regions, growing at Robe. Photo: R.N. Baldock.

Add to that both cold water lying in southernmost parts of southern Australia, which encourages the growth of giant brown algae, and localised upwelling of cold, nutrient rich, deep waters, due to prevailing SE winds in summer, and you have a recipe for large diversity. Odd mixtures of cool- and warm-water species can live together.

South Australian gulfs also harbour relicts from ancient sub-tropical times. One is the brown alga Cystoseira trinodis.

Occasionally drifting algae move great distances from their source. One spectacular example is the brown alga Turbinaria.

The relict brown alga Cystoseira trinodis (LEFT & MIDDLE) and a close-up of Turbinaria (RIGHT), washed into the Great Australian Bight from the Indian Ocean. Photos: R.N. Baldock.

Unfortunately, unwanted algae (“weeds”) such as Caulerpa cylindracea (Algae Revealed fact sheet under the name Caulerpa racemosa var. cylindracea; 365kb PDF) can also drift from the west, too.  Recognising them from closely related species and tracing their spread along our coasts is essential for environmental management.

Caulerpa cylindracea. (LEFT) A mass of plants exposed at low tide. (RIGHT) Detail of the runner by which it spreads, and club-shaped upright parts. Photos: R.N. Blaldock.

Herbaria with their data,  validated by specimens, are storehouses of information and can assist in this.

If you want to know more about the southern marine algae, have a look at Bob Baldock’s illustrated Algae Revealed fact sheets. They can be accessed by clicking the MORE button in the eFloraSA Census search, or through the static index page.

You can also check H.B.S. Womersley‘s monumental Marine Benthic Flora of Southern Australia. Species fact sheets on all southern Australian algae can also be accessed through the eFloraSA Census search, by clicking on the name of the genus or species, or by accessing the static index page.

PDFs of the scanned six volumes of the Marine Benthic Flora are available on EnviroDataSA:

  • Part I – Introduction, seagrasses, green algae (21.2mb PDF)
  • Part II – Brown algae (31mb PDF)
  • Part IIIA – Red algae: Bangiophyceae & Florideophyceae (36.6mb PDF)
  • Part IIIB – Red algae: Gracilariales, Rhodymeniales, Corallinales & Bonnemaisoniales (29.3mb PDF)
  • Part IIIC – Red algae: Ceramiales 1 (36.3mb PDF)
  • Part IIID – Red algae: Ceramiales 2 (40.3mb PDF).

Hardcopy volumes are still available and for sale, please contact stateherbsa@sa.gov.au for more details.

 

Plant of the Month: Sep. 2017

Anthocercis angustifolia in the understorey of a Sheoak woodland in Morialta Conservation Park. Photo: P.J. Lang.

Rays of delight on a rocky path

Anthocercis angustifolia, close-up of flowers. Photo: P.J. Lang.

Our new plant of the month is the rare endemic South Australian shrub, Anthocercis angustifolia F.Muell. (Narrow-leaf Ray-flower). It has a patchy disjunct distribution restricted to a few pockets in the Mt Lofty and Flinders Ranges where it is associated with rocky slopes, escarpments and gorges. One of the best places to see this unusual plant is in DEWNR‘s Park of the Month for August, Morialta Conservation Park. It is currently in flower on the upper walking trail just above Kookaburra Rock lookout and southwards towards the waterfalls. Anthocercis angustifolia is a fire responsive species and it came up in profusion here after this area was burnt several years ago. The illustration above shows it in a successional phase dominating the understorey of an Allocasuarina verticillata Sheoak woodland. The delicate white to creamy-yellow flowers have long narrow corolla lobes from which the genus takes its name based on the Greek anthos, a flower, and kerkis, a ray. When not in flower A. angustifolia may be recognised by its sparse erect habit and slender leaves with small glandular hairs making them clammy to touch. Anthocercis species are known to be poisonous and contain tropane alkaloids.

Anthocercis angustifolia near Gorge Road. Photo: SA Seed Conservation Centre.

Anthocercis is a well-defined apparently monophyletic genus comprising c. 11 currently recognised species. Its centre of diversity is in Western Australia, with most species confined to that State. South Australia also has a second species, Anthocercis anisantha, which extends from WA and has a more compact and spinescent habit. Comprehensive fact sheets on this and other Anthocercis species are available under ‘Identification Tools’ on the efloraSA website, together with an interactive Lucid key to Australian Solanaceae. These useful but often overlooked resources were put together by State Herbarium Honorary Associate Robyn Barker. An illustrated Plant Portrait was published in the Journal of the Adelaide Botanic Gardens 7(3) 309-311 (1985) (580kb PDF). Further information can also be found on the Seeds of South Australia web-site and the Atlas of Living Australia (ALA).

Anthocercis angustifolia. Photo: P.J. Lang.

Contributed by State Herbarium botanist Peter Lang.

Things are never as simple as they appear…

Great fleas have little fleas upon their backs to bite 'em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.



Augustus De Morgan, A Budget of Paradoxes (1872)

The apparently simple specimen that proved to be a whole community of marine organisms. Photo: B. Baldock.

This small specimen was collected from 21 m deep waters, at St Francis Island, Nuyts Archipelago, South Australia (see also South Australia’s offshore islands, p. 150; 33mb PDF). It was torn from its substrate by the frame of an underwater Baited Remote Underwater Video Station (BRUVS) used to film fish populations as part of the survey of Marine Parks, and was given to the Phycology Unit of the State Herbarium of South Australia in 2015.

LEFT: Remains of the slightly calcified exoskeletons of individual zooids in the bryozoan colonies. RIGHT: Part of the inter-connected chambers of the tree-like sponge, walls stained blue. Photo: B. Baldock.

At first sight I thought the specimen was simply a group of “moss animals” or bryozoans (probably Canda arachnoides Lamouroux, above left).  But closer inspection proved that the bryozoans were growing on a tree-like sponge full of inter-connected chambers (above right).

In addition, under the microscope, I found four algae – a veritable community coating the sponge. Labelled with red numbers 1 to 4 in the images, below.

(1) Dictyopteris gracilis, delicate sporelings attached to a sponge skeleton (top), which is stained blue, and a single flimsy blade (bottom). (2) Lejolisea aegagropila, female structure (top) and stalked sporangia (bottom), stained blue. Photo: B. Baldock.

The largest, a Brown alga, Dictyopteris gracilis Womersley (no. 1), consisted of sporelings “babies”, getting established on a relatively stable, hard substrate, a requirement for most algae to survive.  They could have grown into quite elegant, leaf-like plants some 200 mm tall. Their growing centres (meristems) are found in the notch at the apex of the delicate filmy blades. See the Algae revealed factsheet for the species (420kb PDF).

In addition, there was a tangled set of microscopic pink threads, Lejolisia aegagropila (J. Agardh) J. Agardh (no. 2), easily recognised from its female reproductive structures (procarps and cystocarps) that resemble glass light-bulbs.  Mixed in with the female plants was another stage in the species life cycle – a spore plant with packets of 4 spores (tetrasporangia) on minute stalks.

(3) Acrothamnion preisii, elegant feathery (pinnate) side branches tipped with a glistening gland. (4) Audouinella spongicola, minute threads of the Red alga (arrow), running along the blue-stained walls of the sponge which shows ,also, needle-like skeletal spicules. Photo: B. Baldock.

Perhaps the most striking, however, was the Red alga Acrothamnion preissii (Sonder) Wollaston, with its elegant “feathers”, each ending in a glistening gland (no. 3).

The most unusual alga, although obscure, consisted of lines of elongate red cells (no. 4) running on the surface and around the walls of the inter-connected sponge chambers. These belonged to threads of a very simple Red alga, Audouinella spongicola (Weber van Bosse) Stegenga, which, as its name denotes, specifically lives on sponges.

The common, single-celled foraminiferan Discorbis dimidiatus, its shell punctured with minute pores, lives amongst the algae attached to the sponge. Photo: B. Baldock.

There were other microscopic organisms: shell-like unicellular animals (foraminifera), diatoms with glassy walls; and inevitably, bacteria, but I stopped investigations at the plants and animal described above, thinking I had enough evidence to support the sentiment in the adage at the start of this article.

I hope the BRUVS people can continue to send more, minute but nevertheless interesting marine communities to us at the State Herbarium. You never know what will turn up in the marine world.

Contributed by State Herbarium Hon. Associate Bob Baldock.

Plant of the Month: Aug. 2017

Callitris rhomboidea, branch with immature cones. Photo: T. Robinson.

Plant the Month for August is Callitris rhomboidea R.Br. (Oyster Bay pine), which occurs in DEWNR‘s Park of the Month, Onkaparinga River National Park. It is a conifer from the large and cosmopolitan Cypress family (Cupressaceae), which includes many important timber (e.g. Sequoia sp., the Redwoods of North America) and horticultural species (e.g. Cryptomeria, from Japan). Callitris includes approximately 16 species, 13 of which are restricted to Australia. The majority of these occur in heath and woodlands, extending into semi-arid areas. Recent molecular research suggests that Callitris evolved from rainforest ancestors in response to a drying climate over the past 30 million years (Larter et al. 2017) and in contrast to other Australian conifers, they are remarkably drought tolerant, allowing them to thrive in arid conditions.

Callitris rhomboidea, fruiting cone. Photo: T. Robinson.

This species is commonly referred to as the Oyster Bay pine, in reference to its occurrence on the Georges River, in the vicinity of Sydney (also known as Port Jackson pine). Callitris rhomboidea extends from coastal southern Queensland through New South Wales, Victoria and Tasmania. In South Australia, it occurs chiefly on Kangaroo Island and a few scattered localities in the Mount Lofty Ranges, including the Onkaparinga River Gorge, and the Mount Crawford region to the north. While it is widely distributed, Oyster Bay pine is only locally common, occurring on sand dunes and in rocky areas in heath and woodlands. Callitris are intolerant of fire and preferentially grow in areas that are protected by topography or slow rates of fuel accumulation. However, the Oyster Bay pine can readily regenerate from seed, which are held in the thick woody cones that cluster on fruiting branches. Like many plant species of Australia’s fire prone woodlands (for example, Banksia), fire may act as a stimulus for seed release followed by mass germination and generation of dense, even-aged stands.

Callitris rhomboidea in Hale Conservation Park. Photo: T. Robinson.

There are two species of Callitris occurring within the Onkaparinga River National Park. Callitris rhomboidea is perhaps best distinguished from Callitris gracilis (Slender Cypress-pine) by the shape of the cone scales on the female cone, which are rhomboidal (hence the name, rhomboidea) and have a distinct point near the apex.

Callitris rhomboidea is ‘Rare’ within South Australia, and has declined in parts of its range as a consequence of land clearing, grazing and weed competition. While the level of decline is insufficient to warrant listing as ‘Threatened’, factors such as high frequency fires and susceptibility to ‘die-back‘ (caused by the fungal pathogen, Phytophthora cinnamomi) are potential future concerns (IUCN Red List 2017).

Contributed by State Herbarium molecular botanist Ed Biffin.

Our journal’s web-site banners

Swainsona formosa. Photo: H. Owens.

This year, the State Herbarium of South Australia‘s journal changed its name to Swainsona.

When browsing the new journal web-site, you might have noticed that there are changing banners at the top of the page. Each showing a different species of Swainsona. The journal was named after South Australia’s floral emblem, the Sturt desert pea (Swainsona formosa (G.Don) Joy Thomps., but there are about 85 species in the genus (see Joy Thompson’s revision of the genus, 17.7mb PDF). Some of these plants feature on Swainsona‘s web-site.

Below you can find a gallery of the banners that are used at the moment. If you click on the image, you will get more information from the SA Seedbank web-site. More images will be added in the future.

More information on the Australian states’ floral emblems can be found in an article by Sophie Ducker (1999, 930kb PDF) and on the Australian National Botanic Gardens web-site.

Swainsona canescens. Photo: SA Seed Conservation Centre.

Swainsona fuscoviridis & S. fissimontana. Photo: SA Seed Conservation Centre.

Swainsona fuscoviridis. Photo: SA Seed Conservation Centre.

Swainsona leeana. Photo: P.J. Lang.

Swainsona microphylla. Photo: R.J. Bates.

Swainsona oligophylla. Photo: R.J. Bates.

Swainsona pyrophila. Photo: SA Seed Conservation Centre.

Swainsona tenuis. Photo: SA Seed Conservation Centre.

Swainsona tephrotricha. Photo: D.N. Kraehenbuehl.

Swainsona stipularis. Photo: P.J. Lang.